European Journal of Cardiovascular Medicine

The aortic valve is composed of three semilunar cusps attached to a fibrous annulus connected to the distal end of the left ventricular outflow tract. A portion of the annulus is attached to cardiac muscle, while the other half is continuous with the fibrous leaflet of the mitral valve. The functional unit of the valve includes the cusps and their respective aortic sinus complexes, collectively known as the aortic root [1]. Pathological lesions of the aortic valve may result in stenosis, regurgitation, or a combination of both. In the Euro Heart Survey, aortic stenosis was the most frequent lesion, accounting for 43% of all patients with valvular heart disease [2].

Aortic valve replacement (AVR) has traditionally been performed via median sternotomy for more than four decades. With the advent of minimally invasive cardiac surgery in the late 1980s, several minimal access approaches for AVR were developed. The parasternal approach was first described by Cosgrove and Sabik in 1996 [3], followed by the right thoracotomy approach in 1997 [4]. In 1998, Gundry and colleagues introduced the partial ministernotomy approach for adult and pediatric patients [5], while transverse sternotomy was later abandoned due to high morbidity and mortality [6]. Currently, the most widely used minimally invasive approaches are upper ministernotomy and right thoracotomy [7].

The upper partial sternotomy with a J-shaped extension through the fourth intercostal space provides excellent exposure of the aortic root [8,9]. It allows cardiopulmonary bypass to be established through the same incision without specialized instruments or ports, enabling the use of standard surgical techniques with minimal additional risk and facilitating faster recovery in appropriately selected patients [9]. The suitability of the J-shaped approach depends on patient anatomy, body habitus, and cardiac orientation, and preoperative chest radiography helps in surgical planning by defining the relationship between the sternum, aortic root, and ascending aorta, as well as identifying valve calcification [9]. Absolute contraindications include significant coronary artery disease and porcelain aorta, while relative contraindications include unfavorable aortic anatomy, poor left ventricular function, small aortic root requiring enlargement, fragile atrial tissue, severe aorto-iliac disease requiring peripheral cannulation, and certain anatomical variations such as chest wall deformities, cardiac malposition, and obesity.

The ministernotomy approach for AVR aims to achieve faster recovery, reduced ICU and hospital stay, decreased morbidity and postoperative pain, earlier return to normal activities, improved cosmetic outcomes, enhanced patient comfort, and cost reduction [10]. In this context, the present study was conducted to compare early clinical outcomes between ministernotomy and conventional median sternotomy in patients undergoing isolated aortic valve replacement.

Objective

•             To compare early clinical outcomes between ministernotomy and conventional median sternotomy in patients undergoing isolated aortic valve replacement.

This quasi-experimental comparative study was conducted in the Department of Cardiac Surgery at the National Heart Foundation Hospital and Research Institute (NHFH & RI), Mirpur, Dhaka, Bangladesh, over a 24-month period from January 2012 to December 2013. A total of 44 patients undergoing first-time isolated aortic valve replacement (AVR) were included based on predefined inclusion and exclusion criteria to compare early clinical outcomes between the ministernotomy (J-shaped) and conventional median sternotomy approaches. Inclusion criteria i. Patients undergoing first-time isolated AVR ii. Patients who provided informed written consent and agreed to follow-up Exclusion criteria i. Left ventricular ejection fraction <30% ii. Heavily calcified ascending aorta iii. Concomitant valvular disease iv. Associated coronary artery disease requiring coronary artery bypass grafting (CABG) v. Associated congenital heart disease Grouping and Study Variables Patients were allocated into two equal groups: Group I underwent isolated AVR through ministernotomy (J-shaped approach), and Group II underwent AVR through conventional median sternotomy, with 22 patients in each group. Purposive non-random sampling was used. Demographic, preoperative, intraoperative, postoperative, and follow-up variables were recorded and compared between the groups. Surgical Technique AVR in the ministernotomy group was performed through an approximately 9 cm upper partial sternotomy, whereas the conventional group underwent full median sternotomy through a 20–22 cm incision. Standard cardiopulmonary bypass, myocardial protection, and valve replacement techniques were used in both groups. Postoperative Evaluation and Follow-up Postoperatively, patients were managed in the intensive care unit (ICU) and followed up on the 7th postoperative day, at 1 month, and at 3 months with clinical assessment, echocardiography, electrocardiography (ECG), chest X-ray, and INR monitoring. Statistical Analysis Data were collected using a structured proforma and analyzed using SPSS version 17. Continuous variables were compared using Student’s t-test, while categorical variables were analyzed using the Chi-square test or Fisher’s exact test, as appropriate. A p-value <0.05 was considered statistically significant. Ethical Consideration Ethical approval was obtained from the Ethical Review Committee of NHFH & RI, and written informed consent was obtained from all participants.

Table 1: Demographic and Preoperative Characteristics of the Study Participants (n = 44)

The study included 44 patients equally divided between ministernotomy (n = 22) and median sternotomy (n = 22). Patients were predominantly aged ≤50 years in both groups (77.3% vs 86.4%), with mean age 39.22 ± 17.35 years in the ministernotomy group and 45.00 ± 5.71 years in the median sternotomy group (p = 0.146). Males constituted 63.6% and 59.1% of the respective groups (p = 0.757). BMI distribution was comparable, with mean BMI of 21.12 ± 3.77 kg/m² vs 23.02 ± 4.15 kg/m² (p = 0.119), showing no significant baseline differences.

Table 2: Distribution of Preoperative Risk Factors in Study Groups (n = 44)

Diabetes mellitus was present in 31.8% vs 18.2%, hypertension in 31.8% vs 40.9%, dyslipidaemia in 18.2% vs 0%, smoking in 45.5% vs 54.5%, and congestive heart failure in 22.7% vs 9.1% in the ministernotomy and median sternotomy groups respectively. None of the risk factors showed statistically significant differences between groups (all p > 0.05).

Table 3: Distribution of Preoperative Aortic Valve Pathology (n = 44)

Aortic stenosis was the most common diagnosis in both groups (63.6% vs 72.7%), followed by aortic regurgitation (27.3% vs 22.7%) and mixed lesions (9.1% vs 4.5%) in ministernotomy and median sternotomy groups respectively, with no significant difference between groups (p = 0.757).

Table 4: Intraoperative Surgical Characteristics (n = 44)

Mean total operation time was 4.34 ± 0.73 hours vs 4.66 ± 0.51 hours (p = 0.105), and aortic cross-clamp time was comparable (78.27 ± 21.71 vs 78.45 ± 24.46 min; p = 0.979). Cardiopulmonary bypass time was significantly longer in the ministernotomy group (122.45 ± 27.90 vs 104.50 ± 22.96 min; p = 0.025), while incision length was significantly shorter (9.45 ± 1.62 vs 21.72 ± 2.39 cm; p = 0.001).

Table 5: Bleeding-Related Outcomes and Early Recovery Parameters (n = 44)

Blood transfusion requirement was significantly higher in the ministernotomy group (86.4% vs 31.8%; p = 0.001). Postoperative blood loss (557.27 ± 356.92 vs 454.76 ± 247.84 ml), transfusion volume (754.21 ± 407.09 vs 700.00 ± 403.69 ml), and mediastinal drainage duration (30.45 ± 3.20 vs 31.95 ± 4.22 hours) were comparable (all p > 0.05). Mechanical ventilation time (12.09 ± 0.81 vs 12.91 ± 0.92 hours; p = 0.003), ICU stay (2.46 ± 0.93 vs 5.34 ± 3.38 days; p = 0.001), inotrope requirement (31.8% vs 86.4%; p = 0.001), and pain scores (2.95 ± 0.85 vs 5.00 ± 0.81; p = 0.001) were significantly lower in the ministernotomy group, while hospital stay was similar (7.58 ± 2.93 vs 9.78 ± 5.59 days; p = 0.111).

Table 6: Postoperative Sternal Wound Infection Within 30 Days (n = 44)

Superficial sternal wound infection occurred in 9.1% vs 13.6% of patients in ministernotomy and median sternotomy groups respectively, with no deep infections in either group. The difference was not statistically significant (p = 1.000).

Table 7: Thirty-Day Mortality Outcomes (n = 44)

No mortality was observed in either group during the 30-day follow-up period (0% vs 0%; p = 1.000), indicating equivalent early survival outcomes.

Table 8: Serial Echocardiographic Outcomes After Aortic Valve Replacement (n = 44)

Left ventricular ejection fraction (LVEF) showed progressive improvement in both groups from baseline to 3 months postoperatively, with no statistically significant differences at any time point: baseline (59.18 ± 8.53 vs 61.04 ± 7.66), 7th POD (64.00 ± 7.88 vs 63.04 ± 7.66), 1 month (64.04 ± 7.88 vs 63.00 ± 7.67), and 3 months (65.00 ± 7.89 vs 64.00 ± 7.88) (all p > 0.05). Paravalvular leakage was rare, occurring in only one case (4.5%) in the ministernotomy group at 7th POD, with no later occurrences.

Table 9: Postoperative Wound Complications During Follow-up (n = 44)

Early superficial wound infection was observed in 9.1% vs 13.6% of patients at 7th POD, with no infections at 1 month or 3 months in either group. No significant difference in wound-related complications was observed between groups (p = 1.000).

A total of 44 patients were recruited for isolated aortic valve replacement, of which ministernotomy (“J” shaped) was performed in 22 patients. Compared with 22 patients operated on through conventional median sternotomy, the length of incision was shorter, postoperative pain was reduced, ICU stay and hospital stay were decreased, and overall recovery was improved.

In our study, we found that aortic stenosis was the most frequent lesion in both study groups. Bakir et al.[11] followed 506 patients who received aortic valve replacement, of whom 232 underwent ministernotomy and 274 underwent median sternotomy. Of the total 506 patients, the majority had aortic stenosis, which is consistent with the present study. Furthermore, similar to the present result, Donald et al.[2] found that aortic stenosis was the most frequent lesion, accounting for 43.0% of all patients with valvular heart disease.

Total operation time, duration of ICU stay, and hospital stay are increasingly important because they are major determinants of cost in cardiac surgery. In our study, we observed no significant difference in total operation time between groups; however, ICU stay was significantly shorter in the ministernotomy group, while hospital stay was also shorter but not statistically significant. We also observed longer cardiopulmonary bypass (CPB) time in the ministernotomy group, while aortic cross-clamp (ACC) time showed no significant difference between groups. Cosgrove et al.[12] reported a reduction in direct hospitalization costs of approximately 19% due to earlier extubation and reduced ICU stay. This finding is not in agreement with Aris et al.[13] and may be explained partly by longer cardiopulmonary bypass times in the ministernotomy group. Masiello et al.[14] analyzed 200 patients, of whom 100 underwent a ministernotomy approach, and found that operating times were significantly longer in the ministernotomy group. Similar to the present study, Bakir et al.[11] and Brown et al.[15] reported shorter ICU and hospital stays in the ministernotomy group.

We found longer cardiopulmonary bypass (CPB) time in the ministernotomy group, with no significant difference in aortic cross-clamp (ACC) time between groups. Similar to the present result, Brown et al.[15] reported longer CPB times in the ministernotomy group compared with conventional median sternotomy. However, Aris et al.[13] reported longer CPB and ACC times in the ministernotomy group.

In our study, postoperative blood transfusion requirement was significantly higher in the ministernotomy group, although postoperative blood loss, transfusion volume, and mediastinal drainage duration were not significantly different between groups. Bakir et al.[11] conducted a retrospective analysis of 506 patients (232 ministernotomy and 274 median sternotomy) and reported lower mean blood loss in the ministernotomy group compared with median sternotomy. Farhat et al.[16] also reported that ministernotomy is associated with less perioperative and postoperative bleeding.

In our study, 7 patients in the ministernotomy group and 4 patients in the median sternotomy group were diabetic. We observed 2 cases of superficial wound infection in the ministernotomy group and 3 cases in the median sternotomy group. There was no postoperative wound-related complication at 1 month and 3 months of follow-up in either group.

No mortality was observed in either group in our study. Brown et al.[15] found that hospital mortality and morbidity were similar in ministernotomy and median sternotomy groups for aortic valve replacement. The use of inotropic support was higher in the median sternotomy group than in the ministernotomy group in our study. Similar to the present result, Moustafa et al.[17] reported that the ministernotomy group required less inotropic support than the conventional median sternotomy group, which also disagrees with the findings of Szwerc et al.[18].

No patient in the ministernotomy group required re-exploration for bleeding or conversion to full sternotomy. Although the smaller incision may theoretically limit exposure, conversion to full sternotomy can be performed rapidly if necessary. In our study, left ventricular ejection fraction (LVEF) showed no significant difference between groups at baseline and at 7th postoperative day, 1 month, and 3 months after aortic valve replacement. Similarly, there was no paravalvular leakage at 1 month and 3 months follow-up in either group.

In the ministernotomy group, incision length was significantly shorter, and patients reported less postoperative pain with better cosmetic satisfaction. Similar findings were reported by Brown et al.[15], who also demonstrated reduced postoperative pain in the ministernotomy group.

Limitations of the study

This was a single-center study; therefore, the findings may not be generalizable to a multi-center setting.

Based on the findings of this study, it can be concluded that aortic valve replacement can be performed through a ministernotomy (“J”-shaped) approach without compromising patient safety. The results demonstrate several advantages in the ministernotomy group, particularly in terms of reduced incision length, shorter duration of mechanical ventilation, lower postoperative pain, and reduced intensive care unit stay, while hospital stay was comparable. Patients in the ministernotomy group also had a smaller scar, which is likely to contribute to greater overall patient satisfaction. Collectively, these benefits may translate into more efficient utilization of limited healthcare resources.

1.      Butcher JT, Mahler GJ, Hockaday LA. Aortic valve disease and treatment: the need for naturally engineered solutions. Advanced drug delivery reviews. 2011 Apr 30;63(4-5):242-68.

2.      Donald L-J, Todd JA, Mercedes MB, Shifan C. Heart disease and Stroke Statistics-2010 Update. A report from the. American Heart Association Circulation. 2010;121:e89–90.

3.      Cosgrove DM, Sabik JF. Minimally invasive approach for aortic valve operations. The Annals of thoracic surgery. 1996 Aug 1;62(2):596-7.

4.      Benetti FJ, Mariani MA, Rizzardi JL, Benetti I, Benetti FF, Aires B. Minimally invasive aortic valve replacement. The Journal of thoracic and cardiovascular surgery. 1997 Apr 1;113(4):806-7.

5.      Gundry SR, Shattuck OH, Razzouk AJ, Del Rio MJ, Sardari FF, Bailey LL. Facile minimally invasive cardiac surgery via ministernotomy. The Annals of thoracic surgery. 1998 Apr 1;65(4):1100-4.

6.      Bridgewater B, Steyn RS, Ray S, Hooper T. Minimally invasive aortic valve replacement through a transverse sternotomy: a word of caution. Heart. 1998 Jun 1;79(6):605-7.

7.      Kim BS, Soltesz EG, Cohn LH. Minimally invasive approaches to aortic valve surgery: Brigham experience. InSeminars in Thoracic and Cardiovascular Surgery 2006 Jun 1 (Vol. 18, No. 2, pp. 148-153). WB Saunders.

8.      Svensson LG. Minimal-access “J” or “j” sternotomy for valvular, aortic, and coronary operations or reoperations. The Annals of thoracic surgery. 1997 Nov 1;64(5):1501-3.

9.      von Segesser LK, Westaby S, Pomar J, Loisance D, Groscurth P, Turina M. Less invasive aortic valve surgery: rationale and technique. European journal of cardio-thoracic surgery. 1999 Jun 1;15(6):781-5.

10.   Ehrlich W, Skwara W, Klövekorn WP, Roth M, Bauer EP. Do patients want minimally invasive aortic valve replacement?. European journal of cardio-thoracic surgery. 2000 Jun 1;17(6):714-7.

11.   Bakir I, Casselman FP, Wellens F, Jeanmart H, De Geest R, Degrieck I, Van Praet F, Vermeulen Y, Vanermen H. Minimally invasive versus standard approach aortic valve replacement: a study in 506 patients. The Annals of thoracic surgery. 2006 May 1;81(5):1599-604.

12.   Cosgrove III DM, Sabik JF, Navia JL. Minimally invasive valve operations. The Annals of thoracic surgery. 1998 Jun 1;65(6):1535-9.

13.   Aris A, Cámara ML, Montiel J, Delgado LJ, Galán J, Litvan H. Ministernotomy versus median sternotomy for aortic valve replacement: a prospective, randomized study. The Annals of thoracic surgery. 1999 Jun 1;67(6):1583-7.

14.   Masiello P, Coscioni E, Panza A, Triumbari F, Preziosi G, Di Benedetto G. Surgical results of aortic valve replacement via partial upper sternotomy: comparison with median sternotomy. Cardiovascular surgery. 2002 Aug;10(4):333-8.

15.   Brown ML, McKellar SH, Sundt TM, Schaff HV. Ministernotomy versus conventional sternotomy for aortic valve replacement: a systematic review and meta-analysis. The Journal of thoracic and cardiovascular surgery. 2009 Mar 1;137(3):670-9.

16.   Farhat F, Lu Z, Lefevre M, Montagna P, Mikaeloff P, Jegaden O. Prospective comparison between total sternotomy and ministernotomy for aortic valve replacement. Journal of cardiac surgery. 2003 Sep;18(5):396-401.

17.   Moustafa MA, Abdelsamad AA, Zakaria G, Omarah MM. Minimal vs median sternotomy for aortic valve replacement. Asian Cardiovascular and Thoracic Annals. 2007 Dec;15(6):472-5.

18.  Szwerc MF, Benckart DH, Wiechmann RJ, Savage EB, Szydlowski GW, Magovern Jr GJ, Magovern JA. Partial versus full sternotomy for aortic valve replacement. The Annals of thoracic surgery. 1999 Dec 1;68(6):2209-13.